FIG. 4.

(A) PCA factor plot of community carbon source utilization patterns for effluent groundwater (Unattached) and crushed basalt extracts (Attached) from packed columns. Factors 1 and 2 accounted for 44 and 18% of the total variance in the data set, respectively. Individual observations are denoted with the letter P for packed column, followed by the number of the replicate column and either S for solid or W for water. (B) PCA factor plot of community carbon source utilization patterns for effluent groundwater (Unattached) and fracture face-associated biomass (Attached) from fractured core flood units. Factors 1 and 2 accounted for 27 and 24% of the total variance in the data set, respectively. Individual observations are denoted with the letter F for fractured core flood unit, followed by the number of the replicate column and either S for solid or W for water.